Lawn mower



Aug- 10, 1937- J. c. sTAUr-FER 2,089,445

LAW N MOWE R Filed Dec. 28, 193e Patented Aug. 10, 1937 UNITED STATES LAWN MOWER Joseph C. Stauifer, Los Angeles, Calif.

Application December 28, 1936, Serial No. 117,853

15 Claims.

This invention relates to lawn mowers and re- -lates more particularly to power operated lawn mowers. A general object of this invention is to provide a practical, simple and inexpensive lawn mower having an electrically driven cutter.

Power operated or power driven lawn movers of various characters have been proposed and introduced. In most instances lawn mowers of this character have been heavy and cumbersome l0 and, therefore, diflicult to operate and have been expensive to manufacture.

Another object of this invention is to provide a lawn mower embodying an electrically driven cutterthat is small and compact, light in weight and inexpensive to manufacture.

Another object of this' invention is to provide a lawn mower of the character mentioned in which the motor for driving the cutter is mounted directly over the cutter to be carried by the main wheels of the mower as distinguished from prior power driven mowers in which the motors were carried bywheels leading or trailing the main wheels.

Another object of this invention is to provide a power operated lawn mower that requires only two wheels for carrying the various elements and mechanisms of the mower. v.

Another object of this invention is to provide a lawnmower of the character mentioned that embodiesV an extremely vsimple and yet effective mounting for the motor. Another object of this invention is to provide a lawn mower of the character mentioned in which the motor, the pulleys, etc., of the cutter 35 drive, the side plates and the cutter, are all carried by the yoke of thehandle which, in turn, is pivotally carried by the axles of themain wheels, thereby producing an extremely simple and compact arrangement of parts.

vide a lawn mower of the character mentioned in which little or no weight is imposed on the operator through the handle.

The various objects and features of my invening a view taken as indicated by line I-I onv Fig. 2. Fig.'2 is a front elevation of the mower with the handle broken away. Fig. 3 is .an en-- 55 larged fragmentary vertical detailed se tional view taken as indicated byline 32-3 on Fig. 1. Fig. 4 is a fragmentary side elevation of a portion of the mower illustrating an alternative mounting for the pulley shaft, and Fig. 5 is an enlarged fragmentary elevation view illustrating a part of the motor mounting.

The improved lawn mower of the invention illustrated in Figs. 1, 2, 3, and 5, includes, generally, two main wheels III, a handle yoke II carried by the axles of the wheels I0, side plates I2 carried by the yoke II, a rotatable cutter i, I3 arranged between the plates I2, a motor I4 supported by the yoke II, and a drive I5 between the motor III and the rotary cutter I3.

The wheels I0 are the traction elements and the main supporting elements of the mower. 'I'he wheels I0 may be of any suitable design and construction. It is preferred to employ wheels lll that are relatively large in diameter, as illustrated. The particular wheels I0 illustrated in the drawing have inwardly projecting hubs I5 provided with central openings I6.

The handle yoke II carries a. suitable handle I1. and in accordance with the invention the yoke II serves to mount or support the various elements of the mower on the axles of the wheels l0. The yoke II comprises two like oppositely `arranged tine members I8 whose upper ends are secured to the lower end of the handle I'I. The yoke members I8 extend outwardly and downwardly in opposite directions from the handle II and have lower portions I9 that are substantially parallel with'one another. The lower portions I9 of the yoke members I8 are in spaced parallel relation to the inner sides of the wheels I0. The portions I9 preferably project downwardly and forwardly at increasing or sharper angles, as illustrated in Fig. 1. Brackets 20 de- 4pend from the portions I9' of the yoke mem- A further object of this invention is to probers I8. In the particular structure illustrated, the brackets 20 comprise spaced arms 20 whose upper ends are rigidly secured to the portions I9. The bracket arms 20 converge downwardly and their lower ends are integrally joined. Trunnions or axles 2| for the wheels IU project outwardly from the lower portions of the brackets 20. In practice the axles 2I may be threaded in openings 22 in the brackets 20 and may be locked against rotation and displacement by lock nuts 23. The axles 2| extend outwardly through the openings IB in the wheel hubs I5a to rotatably carry the wheels I0. Keys 24 or other suitable` means may be provided on the outer ends of the axles 2I to prevent ther displacement of the wheels I0 from the axles. It will be obI The plates I 2- may be varied considerably in shape and may be formed as found most desirable. The

intermediate portions of the plates vI2 are of substantial width and height and have rounded upper and lower-edges. The plates may have forwardly and upwardly projecting end parts 25 provided with forwardly convergent upper and lower edges. The upper edges of the parts 25 may be substantially horizontal as illustrated. The plates I2 may also have rearwardly projecting parts 2'6 having rearwardly' and downwardly convergent edges. The side plates I2 preferably have marginal anges 21. The anges 21 project from the inner sides of the plates I2 and may extend throughout the edges of the plates. In accordance with the invention, the plates I2 25 are pivotally connected with the lower ends or parts of the yoke members I8. The end parts 25 of the plates I2 project forwardly to the lower ends of the yoke portions I9 and are pivotally connected therewith. In the particular case illus- 0 trated pivot vpins or bolts 28 pass through suitable openings in the end parts 25 of the plates and the lower portions I9 of the yoke members IB to pivotally support the plates on the yoke members. A suitable spacer7 28 may be provided to engage against the inner sides of the plate parts 25l to assist in holding the plates I2 in parallelism. From the above it will be seen thati 'the` two` side plates I2 are pivotally connected with the lower ends of the yoke members I8 and have pivotal movement about a substantially horizontal axis.

The invention provides novel suspension means for slackly connecting orI suspending the rear portions of the plates I2 from the handle yoke II. Two spaced horizontal support members 30 extend between the spaced brackets 20. supporting members 30 may have upturned flanges 3I on their ends rigidly secured to the v inner sides of the bracket arms 20B. Substantially 60 to adjust the rods vertically and, therefore, vary or regulate the normal positions of the plates. The hook parts or fingers 34 of the rods 33 en i gage under theTlanges `21 in planes' adjacent but vslightly rearward of the common axis of the 65 wheels I8. It will be apparent how/ the lingers 34 cooperate with the flanges 21 to limit down- -ward pivoting of the platesy I2 relative'to the yoke I I and to assist in supporting or suspending the 70 plates from the yoke.Y It will be observed that the fingers 34 engaging under the anges 21 allow the plates I2 to swing or pivot upwardly, on the,

pivot pins 28, witli;` respect to the yoke I I. It is to be particularly noted that the plates I2 car- 75 ried by the pins 2.8 and the rods 33, as just de- The i scribed, are entirely supported by the yoke II which, in turn, is carried by the axles 2| of the Wheels I0.

The plates I2 carry ai relatively stationary cutter blade 36. '1"he blade 36 Iextends horizontally between the two plates I2 and is tilted or sloped to be in the proper relation to the rotatable cutter I3. The blade 36 is pivotally or tiltably connected with the plates I2 at 31 and suitable adjusting means 38 are provided to regulate the `set or pitch of the blade. If desired or believed necessary the rearparts 26 of the plates I3 may carry a suitable roller 39. It is to be understood that the roller 39 is not essential and may be omitted if desired. The particular roller 39 illustrated has suitable rotatable mountings 48 on the rear end parts 26 of the plates I2 so that it may roll along the lawn in trailing relation to l y the cutter I3.

The invention may includemeansfor counter- -balancing or partially counter-balancing the Weight of the plates I2 and the parts carried thereby so that the plates may more easily lift vare adjustably connected with the yoke members I8. In the structure illustrated, brackets 12 project inwardly from the inner sides of the above described yoke portions. I9 and yadjustable screws 13 are carried bythe brackets 12 to attach the upper ends of the springs 1I to the yoke members. The springs 1I normally exert an upward pulling force or lifting force on the plates I2 to partially counter-balance the weight of the plates and the parts carried thereby.

The cutter I3 is' the rotatable cutting element ofthe mower and cooperates with the relatively stationary blade 36 to cut the grass. The present invention is not primarily concerned with the details of the rotary cutter and any suitable form of rotary cutter may be employed. The particular rotary cutter illustrated includes. a shaft or axle 4I, spokes 42 radiating from the -axle 4I and helical or spiral blades 43 carried by th spokes 42. The opposite end portions of the cutter axle 4I are vrotatably supported by's table bearings 44 on the plates I2. One end p tion of the axle 4I projects from the outside v0f one of theplates I2. It will be observed that the axis of rotation of the rotary cutter, I3 is directly or substantially directly below the axis of rotation ofthe wheels I0. The cutter I3 is, ofcourse, positioned so that its blades 43 have proper cooperation with the relatively stationary blade 36.

The motor I4 is provided to drive or rotate the cutter I3 through the medium of, the drive I6. I'he motor I4 is a suitable electric motor of the required H. P. and R. P. M. rating. It is, of course, desirable to employ as small andas light a motor as practicable.` The positioning or mounting of the motor I4 is'important. The

motor I4 is supported on the members 30 to bev substantially directly above the common axis of the wheels I0. Thus the weightof the motor is not imposed on the handle I'Il in amanner to cause tipping of the mower or to impose its weight on the operator of the mower. The motor I4 is preferably located adjacent the side plate I2 from which the cutter axle 4I.projects. Further, the

motor I4 is positioned with its axis parallel with the axes of the cutter I3 and the wheels III. The cord or wires 45 for carryi energizi rent to theA motor I4 may be suitably trained or '1 5 directed to extend to a convenient source of electrical energy. The motor is preferably mounted for adjustment in a direction trans- In the case illustrated, the

motor I4 is mounted on skids or plates 418 on l the supporting members 30. Securing bolts 49 pass through slots I9EL in the base of the motor and openings in the plates 41a, whereby the motor may be shifted or adjusted in the direction just chain and socket drive if the structure illustrated, the drive I5 includes a 20 pulley 41 -xed on the shaft 48 of the motor A bracket 49 is mounted on the adjacent portion I9 o`f a yoke member I8; A bearing 50 on the bracket 449 carries a rotatable shaft 5I'. A pulley 52 is fixed to the shaft 5I to be in alignment with 25 the pulley 41 on the motor shaft 48. vThe pulley 52 is considerably larger in ameter than the pulley 41. A suitable belt 52L operates over the pulleys 41 and 52, whereby the motor I4 drives the shaft 5I. A pulley 53 is fixed on the shaft 30 5 I at the outer end of the bearing 50. The pulley 53 is preferably smaller in diameter than the pulley 52. A pulley '54 ls fixed on th mentioned projecting 4I to be at the outer side of the adjacent plate I2. 35 The pulley sa is in alignment with the pulley s Vand is considerably larger than the pulley 53 A suitable belt 55 operates over the pulleys 53 and 54, whereby the shaft 5I driven by the motor I4, drives the shaft 4I of the cutter I3. It is to 40 be understood that the ratio of effective diameters of the several pulleys 41, 52, 53 and 54 may be such that the rotary cutter I3 is driven at the proper speed.

The brackets 49 carrying the bearing 50 is 45 mounted so that the axis of the shaft 5I is adjacent the pivotal axis of plates I2. Because of' this relationship any lifting of the plates I2 due to the operation of the blade 35 or the roller 39 over stones or the like does not disturb the 50 spacing of `the pulleys 53 and 54 to any appreciable degree and, therefore, does not cause exslack in the belt 55. In the construction illustrated in Figs. 1 and 2 of the .drawing the bracket 49 is `secured lto the lower 55 portion I9 of the adjacent yoke bracket 49 is arranged against. the outer side of flange 51 seating of the portion I9. are provided in 60 the bracket 49 and screws 59 are threaded in in the portion .I9 and pass through the to adjustably secure the bracket 49 to Isaid portion. By suitably adjusting the bracketV 49 the tension of the belt 55 may be varied at 65 will Y Fig. 4 of the drawing illustrates a slightly modi- In the structure illustrated in Fig. 4 the bearing 50 for the pulley shaft 49B. The bracket 49* 5 of the adjacent side --The portion of the flange 21 on which the bracket is straight and normally substantially horizontal. In accordance with the '1.5 invention, the bracket 49B is adjustably secured plate I2.

' openings in end part of the cutter shaft j 3 ner that member I I. The

extending along the' Screws 59% are threaded in through slots heads engage against the upper will be apparent how the bracket 43 may be adjusted to provide for the proper tensioning of It is believed that the operation of the lawn mower provided by this invention will be readily understood from the foregoing detailed description. Referring to Figs. l, 2, and 5 it will be seen that the motor I4 is operable to drive or rotate the cutter I3 through the drive I5 comprising the pulleysl 41 and 52, carrying the belt 52a and the pulleys 53 and 54 carrying the belt 55. The motor I4 only serves to rotate or cutter I3, and the traction wheels ID driven by the motor. Accordingly, the mower is under the full control of the operator. The motor I4 is supporte d bythe members 30 to be directly over the common axis of the to the flange 21.

' the flange 21 and pass wheels III so that its weight is not imposed on the handle I1 and does not tend to cause tipping of the mower. Because of the central location of the motor to provide leading or wheels or rollers to carry the motorf y The side plates I2 which carry the rotary cutter I3 and the stationary blade 36 are supported by the yoke II by simple, dependable means' so that they may swing or oscillate when necessary; The rods 33 limit the downward pivotingl of the plates I2 and normally suspend the plates where the cutter I3 and the blade to cut the grass. The bolts 28 and the rods 33 secure the plates I2 to the yoke II in such a manthe weight of the plates and the parts of gravity located to maintain the mower in a proper state of equilibrium. It will be observed that the cutter I3 and the center of gravity o'f-v the plates I2 are substantially directly below the axis of the wheels I9 so that the weight of these parts is not imthe medium of connected therewith has its center posed on the operator through the handle I1. suspend the rear portions of the plates I2 from the yoke I I so that the operator may swing or pivot the handle I1 to change the associated parts when the mower is operated over inclines, terraces, or the like. has control over the action of the event that the the like, the plates I3 are free to pivot upwardly abo or bolts 29. The springs 1I partially counterbalance the plates I2 and the parts carried thereby and .allow the4 readily raise or pivot upwardly. pulley shaft 5I is adjacent the pivotal axis ofthe plates I2 so that pivoting of the parts carried thereby disturbs the belt 55 to a minimum extent. i

It is to be particularly noted that the mounting for the motor I4 and the means supporting the plates I2 and the parts carried thereby are exin weight and inexpensive.

tary cutter I3, the stationary blade 36 and the roller 31. Thus t e handle yoke II carries the 35 are properll7 p0sitioned otor Having described only typical preferred forms wheels, a yoke arranged with its tmes at the and app 'cations of my invention, I do not wish inner sides of the wheels and pivotally carried to be limited or restricted to the specic forms t ereby, side plates pivotally connected with the motor and the rotary cutter, and cooperating parts carried by the yoke and plates pending the rear portions of th yoke. y

for limited pivotal movement about an-axis a spaced forwardly of the com 55 wheels, a relatively stationary blade extending betweenthe plates, the plates to substantially directly above the a d a drive between shaft car- 75j l ried by the bearing to have its axis adjacent the pivotal axis of the adjacent plate, a drive between the motor and said shaft, an element xed to said shaft, an element fixed to the shaft of the cutter, and a flexible member operating over said elements.

12. A lawn mower comprising, two spaced wheels, a yoke arranged with its tines at the inner sides of the wheels and pivotally carried thereby, side plates pivotally connected with the outer portions of the yoke tines, slack connections between the plates and the said tines limiting downward movement of the plates and allowing the plates to pivot upwardly relative to the yoke, a relatively stationary blade carried by the plates. a rotatable cutter carried by the plates to cooperate with said blade, a motor on the yoke, and a drive-between the motor and the cutter, the drive including a bearing, means adjustably mounting the bearing on a tine, a shaft carried by the bearing to have its axis adjacent the pivotal axis of the adjacent plate, a belt and pulley drive between the motor and said shaft, and a belt and' pulley drive between said shaft and the cutter.

13. A lawn mower comprising, two spaced wheels, a yoke arranged with its tines at the inner sides of the wheels and pivotally carried thereby, side plates pivotally connected with the outer portions of the yoke tines, projections on the plates, suspension members depending from the said tines and cooperating with the under sides of the projections to limit downward movement of the plates. and otherwise free of the plates to allow the plates to pivot upwardly relative to the yoke, a relatively stationary blade carried by the plates, a rotatable cutter carried by the plates to cooperate with said blade, a support member extending between and connected to the tines of the yoke,

a motor on said member, and a drive between the motor and the cutter.

14. A lawn mower comprising, two spaced wheels, a yoke arranged with its tines at the inner sides of the wheels and pivotally carried thereby, side plates pivotally connected with the outer portions of the yoke tines, slack connections between the plates and the said tines limiting downward movement of the plates and allowing the plates to pivot upwardly relative to the/yoke, a relatively stationary blade carried by the plates, a rotatable cutter carried by the plates to cooperate with said blade, a motor on the yoke, and a drive between the motor and the cutter, said drive including a bearing on one of said plates, a shaft carried by the bearing tohave its axis adjacent the pivotal axis of said plate, a drive between the motor and said` shaft, and a drive between said shaft and the cutter.

15. A lawn mower comprising; two spaced Wheels, a yoke arranged with its tines at the inner sides of the wheels and pivotally `carried thereby, side plates pivotally connected with the outer portions of the yoke tines, slack connections between the plates and the said tineslmiting downward movement of the plates and allowing the plates to pivot upwardly relative to the yoke, a relatively stationary blade carried by the plates, a rotatable cutter carried by the plates to col operate with said blade, a motor on the yoke, and a drive between the motor and the cutter, said drive including a bearing, means adjustably securing the bearing to one of said plates, a belt and pulley drive between the motor and said shaft, and a belt and pulley drive between the said shaft and the cutter. f

JOSEPH C. STAUFFER. 

